Electric cut-out



Aug. 22, 1939. R BENNETT 2,170,676 ELECTRIC CUT-OUT Filed Dec. 20, 1938 Hill . Irwverwtov: 33 .a/ 4/ 40 4g S.Benhetp,

fi by Hi; Attorn ey.

Patented Aug. 22, 1939 UNITED STATES ELECTRIC CUT-OUT Ralph S. Bennett, Pittsfield, Mass, assignor to General Electric Company, a corporation of New York Application December 20,

4 Claims.

The present invention relates to electric cutouts and more particularly to fuse cutouts of the enclosed drop-out type.

In some installations of enclosed drop-out fuse cutouts, difficulties have been experienced due to the entrance into the cutout housings of insects such as wasps which build nests of mud or other material inside of the housings and thereby cause. electrical or mechanical failures.

It is therefore an object of the present invention to provide, in an enclosed drop-out cutout, an improved construction and arrangement of barrier means which will keep out insects but which at the same time will not interfere with either the manual or the automatic operation of the cutout.

The details of that which I believe to be novel and my invention will become apparent from the following description and the claims appended thereto, taken in conjunction with the' accompanying drawing in which Fig. 1 shows a sectional elevation of an exemplary form of enclosed drop-out cutout embodying the improved barrier means of my present invention; Fig. 2 shows in perspective the fuse and door assembly of the exemplary cutout, and Fig. 3 shows a cross-section taken along the line 3-3 of Fig. 1.

As will be seen by reference to the drawing, the illustrated cutout has a casing ID of porcelain' or other suitable insulating material to the rear of which is secured a mounting bar II for attachment of the cutout to any suitable support. The inner wall of'this casing is formed with an electric creepage and gas barrier I2 upon opposite sides of which are mounted terminal contacts l3 and I4. These terminal contacts I3 and M are provided with clamping sockets l5 and I6, respectively, for attachment of connection leads thereto. Upper contact I3 is provided'with a pair of resilient latching fingers one of which is shown in the drawing, for engagement with the upper end of a fuse holder, and is provided also with a contact finger l8 backed by means of a spring strip l9. On the inner wall of the casing, adjacent the lower end thereof, is a hinge bracket 20.

The fuse assembly of the illustrated cutout includes a tubular expulsion fuse holder 2| carried by bosses 22 and 23 formed integrally with '25, the upper end of which is pivotally attached to door boss 23 by means of screws 26 and the lower end of which lever is hingedly mounted on 1938, Serial No. 248,873

bracket 20. Normally the hinged lever is held against movement relative to the fuse holder by means of a fuse link in the holder, one end of which fuse link, designated 21, is clamped to the hinged lever by suitable terminal clamping means 5 indicated at 28. A contact arm 29, pivotally mounted on the toggle lever as indicated at 30 and biased by coil spring 3|, is provided for effecting electric connection between the lower end of fuse link 21 and lower stationary contact |4 carried by the casing. A good electric connection between lever 25 and contact arm 29 is provided by a flexible metallic shunt strip 33, the opposite ends of which are connected with the lever and the contact arm by means of screws 34 and 15 35, respectively, or other suitable means. Connection of the upper end of fuse link 21 with upper stationary contact I3 is effected through engagement of contact finger I 8.with the terminal cap 36 on the upper end of fuse holder 2|. .The

fuse assembly is latched in operative position by engagement of fingers I! with terminal cap 36, and door 24 is provided with a handle 31 for manual operation of the fuse assembly into and out of operative position. As is well known to those skilled in the art, operation of the fuse link in holder 2|, when'the fuse assembly is in the connected position illustrated, releases toggle lever 25 so as to permit relative movement between the lever and fuse holder. The lower end 80 of the fuse holder thereupon swings outwardly and downwardly so as to release terminal cap 36 from latching fingers l! and permit the fuse assembly and door to swing about hinge bracket 20 to a dropped out position. 3!.

As will be seen from Fig. 1, casing Ill and door 24 form a compartment which is open at the lower end for discharge of gases from fuse holder 2|. Heretofore the opening at the lower end of this compartment has permitted entrance into 40 the cutout casing of wasps or other insects which build nests of mud or other material in the casing. Such nests, if built between the stationary contacts |3 and It, may cause short-circuiting or arc-over between the contacts. Also, the nests may be built so as to interfere with release of the upper latch or with collapse of the toggle mechanism so as to prevent drop-out of the fuse assembly upon fuse operation. To overcome this difliculty I' have provided improved barrier means in the form of a relatively thin and flexible plate 40 which may be constructed of metal or insulation material and which extends transversely of the fuse compartment into proximity or contact with the inner walls of casing iii and the inner face of door 24, as best shown ill'Fig. 3. This barrier plate is supported intermediate lower contact M and the lower open end of the fuse compartment so as to prevent entrance of insects into the portion of the compartment occupied by the stationary contacts, the fuse terminals and the upper pivotally attached end of lever 25. Support of the plate is eiiected by attachment thereof to lever 25 by means of the screw 36 which secures the lower end of shunt strip 33. The barrier plate is formed with a slot having a rectangular portion ll extending normally to the side walls of the casing and arranged to relatively closely accommodate lever 25. Another portion of this slot, designated 132, is formed to relatively closely surround fuse holder Zn. The front of the portion Q2 of the slot is open, while the rear of this portion G2 is connected by means of a narrow portion 63 with the portion ll of the slot. This construction provides for movement of the lower end of the fuse holder outwardly in slot portion 32 and relative to lever 25 when the lever is released upon fuse operation. a v

Thus it will be seen plate Gil, while providing an effective barrier against the entrance of in= sects into the interior of the cutout housing, at the same time interferes in no way with collapse of the toggle mechanism upon fuse operation. This form of barrier has the additional advantages that it is light, inexpensive, and may be readily applied to common forms of drop-out cutouts employing a toggle lever for releasably supporting the fuse assembly. Also, the barrier plate is somewhat flexible, as heretofore men= tioned, so that it readily accoodates itself to variations in dimensions commonly found in cutout casings. This is of importance in that it insures against interference, by the barrier plate, with manual opening and closing of the cutout, as well as the automatic operation of the cutout. Further advantages of the barrier plate are that it acts to retard the rise of expulsion gases from the lower end of the fuse holder into the fuse compartment to cause arcover between the stationary contacts or other conducting parts, and that it minimizes circulation of corrosive and dust laden air through the cutout housing, thereby prolonging the useful life of the cutout.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a drop-out cutout, a casing having spaced contacts therein, a door for an open side of the casing, said casing and door forming a compartment open adjacent one end of the casing, a fuse assembly including a fuse holder and spaced terminals therefor arranged for connection with said contacts, a hinge lever pivotally connected with said assembly and'hingedly mounted on said casing adjacent said open end of said compartment for supporting said assembly in the compartment, said lever being releasably held against movement relative to said holder by means releasable upon fuse operation, and a barrier plate mounted on said lever adjacent said open end of said compartment and. extending transversely antenna of the compartment into proximity with the walls of said casing and the inner side of said door.

2. In a drop-out cutout, a casing having spaced contacts therein, a door for an open side of the casing, said casing and door forming a compartment open adjacent one end of the casing, a fuse assembly including a fuse holder and spaced ter= nals therefor arranged for connection with said contacts, a hinge lever pivotally connected with said assembly and hingedly mounted on said casing adjacent said open end of said compartment for supporting said assembly in the compartment, said lever being releasably held against movement relative to said holder by means releasable, upon fuse operation, and a relatively thin flexible barrier plate mounted on said hinge lever and extending transversely of said compartment into proximity with the walls of said casing and the inner side of said door, said plate being located intermediate the open end of said compartment and the space occupied by said contacts.

3. In a drop-out cutout, a casing having spaced contacts therein, a door for an open side of said casing, said casing and door forming a compart= ment open adjacent one end of the casing, a fuse assembly having spaced terminals for connec= tion with said contacts, a hinge lever pivotally connected with, said assembly and hingedly mounted on said casing adjacent said open end of said compartment for supporting said assembly in the compartment, said assembly including an expulsion fuse holder arranged to discharge at said open end of the compartment and said lever being releasably held against movement relative to said assembly by means releasable upon operation of a fuse link in said holder, and

a barrier plate extending transversely of said compartment adjacent said open end of the compartment, said plate having a portion thereof in at least partially surrounding relation to said holder and formed to provide. for relative movement between the holder and said lever.

4. In a drop-out cutout, a casing having spaced upper and lower contacts, a door for an open side of said casing, a fuse holder, said door and fuse holder forming part of an assembly for mounting in said casing, means for connecting a fuse linkin said holder between said contacts, means for supporting said assembly with said'holder in operative position and said door in closing relation to said open side of the casing, said supporting ted portion fitting relatively closely around said lever and said holder and formed so as .to permit relative movement between the lever and holder.

RALPH s. BENNETT. 

